Circuit controller



Feb. 14, 1933.

s. s. GREEN 1,897,118

CIRCUIT CONTROLLER Filed June 13 1928 i1 35 E V firm/L575. Gees/v,

Patented Feb. 14, 1933 UNITED STATES PATENT OFFICE STANLEY S. GREEN,INDIANAPOLIS, INDIANA, ASSIGNOB TO DUNCAN ELECTRIC MANUFACTURINGCOMPANY, OF LA FAYETTE, INDIANA, A CORPORATION 01 ILLINOIS Applicationfiled June 13,

It is the general object of my invention to produce a dependableliquid-conductor reclosable cutout or circuit controller for electriccircuits, desirably operable both automatically and manually to opensuch a circuit but requiring a certain definite movement or movements inorder to close the circuit.

In practicing my invention, in the preferred way, I produce a reclosablecutout which will act automatically to break the circuit ata definitecurrent value with an action similar to that of a fuse and which mayalso be operated as a switch to break such circuit, which upon certaindefinite movements will positively reclose the circuit which it hasbroken and will only do so upon those definite movements so that oncethe circuit is broken it cannot 'be automatically or accidentallyreestablished, which will do this without the necessity of renewing anyof its parts, which has no relatively movable parts within it other thanthe liquid conductor 1tself, which provides a current-limiting portionof liquid conductor of definite cross-section, so that upon excessivecurrent a vapor1z ing of such liquid conductor takes place at a definitecurrent value to disrupt the current path and to displace the liquidconductor in such a manner that it cannot flow back to reestablish suchpath until the device as a whole is given the proper movements, whichupon proper movements of the device provides a sufficient hydrostatichead to force the liquid conductor through the opening of limited sizewhich provides said first-named portion of liquid conductor of definitecrosssection, and .which requires but a small amount of the liquidconductor, to make the device foolproof so that it is incapable of1mproper manipulation and so that in any position of the device thecircuit cannot be mamtained if the current value is beyond that forwhich the device is designed; and to accomplish these results by astructure which is safe, small, and inexpensive.

In carrying out my invention I preferably use mercury as the liquid conactor; and place it within a holding means, desirably sealed, andincluding a main container and omonrr CONTROLLER 1928. Serial N0.285,114.

a smaller container or conduit, into which electrodes project, so that acircuit may be completed between them through the mercury. The mercurydoes not fill the holdmg means, but leaves considerable gas space toavoid excessive pressure upon vaporization of a portion of the mercury.The smaller container or conduit is provided with a tubular passage ofdefinite cross-section, which tubular assage must-be filled with mercuryin or er to complete the circuit between the two electrodes. Mercury maybe withdrawn from-the tubular passage by proper movement of the deviceas a whole, to break the circuit in a manner similar to the opening of aswitch. In addition, if the circuit is closed by mercury in such tubularpassage,

an excessive current will cause vaporization of the mercury in suchpassage, and the resultant increase in volume forces the mercury out ofthe passage and thus disrupts the circuit. The tubular passage is soarranged with respect to the rest of the holding means that when thedevice is in circuit-closing or normal on position the mercury when onceblown out of the tubular passage in the manner just described, thusbreaking the circuit, cannot flow back into such passage to re-establishthe circuit as long as the device remains in that position. Tore-establish the circuit, the device must be moved to another orpreliminary position, which is an oil position, to cause the mercury toflow into a passage-feeding location; from which the mercury will flowinto the passage, so that upon returnin the device to circuit-closing ornormal on position the circuit will be reestablished. In the preferredform of my invention, which is the form illustrated, the

invention in apreferred form, independently of any mounting and of anydefinite currentsupplying means, as they may take many forms. In suchdrawing, Fig. 1 is a front elevation of a cutout or circuit controllerembodying my invention; Fig. 2 is a section on the line 22 of Fig. 1;and Figs. 3 4, 5, and 6 are front elevations of the cut-out of Fig. l,with the front shell-part removed and with certain of the parts insection substantially on the line 44 of Fig. 2, showing the conditionsand positions of the parts in the off position, an intermediate positionbetween foif and normal on position, the normal on position with thecircuit closed, and the normal on position with the circuit blown open,respectively, the position shown in Fig. 4 corresponding to thatillustrated in Figs. 1 and 2.

In this preferred form of my invention, there is an insulating shellformed of two mating parts 10 and 11, the latter fitting tightly withinan annular groove 12 of the former. These shell parts may be of suitableinsulating material, such as bakelite; and if desired may be sealedtogether, as with varnish. The two parts 10 and 11 provide between thema generally arcuate main container or chamber 14 of fairly largecrosssection extending generally about180, and a feed conduit 15 alsogenerally arcuate but of much smaller cross-section extending for thegreater part of the remaining "180. (The statements of degrees of extentof the chamber 14 and feed passage 15 are merely explanatory, and arenot given as limitations.) The counter-clockwise end of the container orchamber 14, as viewed in Figs. 3 to 6 inclusive, is desirably in generalin the shape of a funnel, to facilitate feeding from such chamber intothe feed conduit 15. At the clockwise end of the container or chamber 14a tube 16 of refractory insulating material is mounted, so that the onlycommunication between the clockwise end of such chamber 14 and thecounter-clockwise end of the feed passage 15 is through such tube 16. Asuitable material for this tube is some heatresisting glass, porcelain,or lava, as it is within this tube that the heat is generated upon theautomatic blowing of the device. The tube 16 is supported at one end byfitting in mating recesses in the two shell-parts 10 and 11, and at thatend communicates with the counter-clockwise end of the feed conduit 15;and is axially held in such recesses by an internally projecting lug orfinger 16 which is provided on a shell-partand bears against but doesnot close the other end of the tube. Thus save at the first-named end,the tube 16 projects into the chamber 14, and

is spaced therefrom, so that a pocket 14 is provided around the tube atthe clockwise end of such chamber 1'4. This pocket around the tube 16 isdesirably of sufiicient size to means contain all or nearly all of themercury 17 which is placed in the device; so that mercury cannot enterthe tube 16 directly from the chamber 14, but can only enter it from thefeed conduit 15. The tube 16 is provided with an opening or tubularpassage through it for its Whole length, which tube opening at anintermediate portion 18 is restricted for a considerable distance toprovide the current-limiting conductor of definite crosssectional areawhen that portion of the tube is filled with mercury. This portion 18 ofsmaller cross-section communicates at both its two ends withlargerportions19 and 20, the latter being a continuation of the feedconduit 15. The current-capacity of the device depends on thecross-section and to some extent on the length of the portion 18. Theparts 15, 20, 18, and 19' together form the passage of a conduit whichopens at both ends intothe main container or chamber 14. The feedconduit 15 and the tubular passage through the tube 16 may be of anydesired shape in cross-section; and while such crosssection is normallycircular it is by no means necessarily so.

It is especially to be observed that the mercury-containing passage 18,by being formed through a body that surrounds such passage substantiallythroughout the length of the passage, defines a limiting size ofcrosssection for the body of mercury within the passage. That is, thesize and shape of this mercury body is defined so that it is ofsubstantially unvarying current-carrying capacity. By thus surroundingthe passage, the efifect which gravity would have on the size of thecross-section at various points in an uncovered passage is eliminated;so that it becomes possible, and indeed preferable as is shown in thedrawing, to set the passage in an inclined position, and secure the mosteffective o eration of the device, while yet maintainmg the shape andsize of the mercury in the passage substantially undisturbed by suchinclination.

Suitable electrodes 21 and 22 are exposed in the respectivetube-portions 19 and 20, being shown as projecting into such tubeportions. When the tube is filled with mercury, such mercur is incontact with the two electrodes 21 an 22, and completes the circuitbetween such electrodes by way of the thread of mercury in thecontracted portion 18 of the tube. The two electrodes cannot beconnected together within the device, regardless of the position of thedevice, save by the mermade of, or at least coated with, some metalwhich resists amalgamation with the mercury; and are desirably ofsufficient proportions that most of the heat of the electric currentwill be generated in the current-limiting thread of mercury, and therewill be no danger of fusion of the electrodes. For instance,the-electrodes may be made of iron, or of nickel-plated copper.

The electrodes 21 and 22, in the form of my invention shown, are mountedon studs 23 and 24, which respectively project into the chamber 14 andinto an enlargement 25 at an intermediate point along the feed conduit15, through bosses 27 and 28 provided on the face of the shell-part 10.These studs 23 and 24 may furnish the connection points for the device;which connections may be made in any suitable way, showndiagrammatically as two flexible wires 29 and 30 respectively attachedto the studs 23 and 24 by binding screws 31 and 32, although this modeof making the connections to the electrodes 21 and 22 is merelyillustrative of a great number of connection modes which might be used.-

The inner ends of the studs 23 and 24 carry the electrodes 21 and 22. Tothat end, in the fdrm of my invention shown, the inner parts of suchstuds are shouldered, and provided with threaded extensions whichreceive nuts 33 and 34, which clamp the supporting ends of theelectrodes against the shoulders on said studs, with the other ends ofsuch electrodes projecting into the two ends of the tube 16. The nuts 33and 34 are shown as elongated beyond the threaded ends of the studs, toreceive clamping screws 35 and 36 which cooperate through such nuts withthe studs 23 and 24 to clamp the two shell-parts 10 and 11 together. Theheads of the screws 35 and 36 are conveniently located in recesses inbosses 37 and 38 provided on the shell, and desirably have a fairlytight fit within such recesses to provide a seal to a considerableextent. Such seal may be made more effective if the heads of the screwson the inner walls of said recesses are freshly varnished just beforethe screws are set.

The device may be supported in any convenient manner, so that it may beturned, manually or otherwise, to the various positions illustrated inFigs. 3, 4, 5, and 6. This turning will be permitted by the mode ofconnection to the studs 23 and 24, which connection as shown is byflexible wires al-' though that method of connection is merelyillustrative. No complete mounting for the device is shown, as noparticular form of mounting is essential to my invention; and indeed, inthe broader aspects of my invention, no mounting at all is necessary.Mere I ly for the sake of illustration, a supporting horizontal shaft 41is shown in dotted lines extending through the central opening 42 withwhich the shell may be provided, but

this manner of support through a central hole is not at all essential.

If desired, the air may be exhausted from within the container; or someinert gas, such as nitrogen, may be provided in place of such air.

In operation, the device is in the condition and position shown in Fig.5 when the circuit is closed. This is the normal on position. Under thatcondition, mercury stands inthe counter-clockwise end of the feedconduit 15, and extends therefrom through the tube 16 into contact withthe electrode 21, so that the adjacent ends of the two electrodes 21 and22 are both immersed in mercury, and the two electrodes are connectedtogether. Indeed, the electrode 22 is wholly immersed in mercury, andthe immersing mercury aids that electrode in carrying current. Theexcess of mercury is spilled over from the free end of the tube 16 intothe pocket 14 surrounding such tube, and lies in the bottom of suchpocket, as is clear from Fig. 5.

To open the circuit manually, the device is tilted from the normal onposition shown in Fig. 5 to the off position shown in Fig. 3. Thistilting may be in either direction, clockwise or counter-clockwise; butwould probably usually be counter-clockwise. This empties the mercuryfrom the tube 16, and the mercury collects by gravity in thecounterclockwise end of the chamber 14; so that there is no connectionbetween the two electrodes 21 and 22, and the circuit is broken. Thebreaking of the circuit occurs within the refractory tube 16.

To reclose the circuit, the device is turned from the off position shownin Fig. 3, through the position in Fig. 4, to the normal on positionshown in Fig. 5. This causes the mercury to flow, by gravity, from thecounter-clockwise end of the chamber 14, beingdirectedby the funnelshape of that end, into the feed conduit 15, and therethrough into thetube 16, and through such tube to reconnect the two electrodes 21 and22. As the device passes through the position shown in Fig. 4, wherecapillary action tends to prevent the flow of mercury through thecontracted portion 18, a hydrostatic head of mercury is provided at theclockwise end of the feed conduit 15 and provides sufiicient hydrostaticpressure to overcome such capillary action and force the mercury throughsuch contracted portion. By having the feed conduit 15 small incross-section, a large head is ob-'- tainable with a small quantity ofmercury. As the device approaches the normal on position shown in Fig.5, any excess of mercury is spilled over from the free end of the tube16 into the pocket 14 provided around such free end at the clockwise endof the chamber 14; and such spilled-over or excess mercury is shown insuch pocket in Fig. 5.

If any sludge collects on the .mercury, it will for the most partcollect on the surface of the mercury in the off position shown in Fig.3, and will rarely if ever enter the-tube 16. If any-does enter suchtube, it will be forced out and through the tube in the manipulation ofthe device, by the hydrostatic head above referred to.

If an excess current flows through the cutout, such as would cause theblowing of a fuse, it produces a vaporization of some of the mercury inthe contracted portion 18 of the tube 16. The amount of current toproduce this depends upon the cross-sectional area of the tube; so thatthe size of such contracted portion will depend upon the value of themaximum current to be permitted. Upon such vaporization, the mercurywhich is vaporized expands in volume and forces the mercury out of thetube 16. The mercury forced out toward the right (Fig. 5 or Fig. 6)drops into the pocket around the tube, as is clear from Fig. 6; fromwhich pocket the mercury cannot return directly into the'tube 16,because the pocket around the tube is of suflicient capacity to holdsuch blown-out mercury. Some mercury may and ordinarily does stillremain in the counter-clockwise end of the feed passage 15 and theadjacent end of the-tube 16, but not enough to extend to the electrode21, and therefore not enough to re-establish the circuit. In thiscondition the circuit is open, although the device is still in normal onposition.

In order now to reestablish the circuit, the device must be turned firstsubstantially to the off position shown in Fig. 3, to dump the mercuryfrom the aforesaid pocket 14 (and indeed from the feed conduit 15) intothe counter-clockwise end of the chamber 14; whereupon by turning thedevice clockwise from the position shown in Fig. 3 through that shown inFig. 4 to the position shown in Fig. 5 the c'rcuit is reestablished inthe manner already described; and this is done without the renewing ofany part.

For the sake of clearness of explanation, I have indicated on Fig. 1 twoarrows marked respectively Normal on and 0d, and have shown on the shella line 50 which may be moved to those two positions. When the line 50 isopposite the normal on arrow, the shell is in the position shown inFigs. 5 and 6; while when it is opposite the off arrow, it is in theposition shown in Fig. 3. When the circuit is opened manually, thedevice is moved tothe off position shown in Fig. 3, with the line 50opposite the off arrow. When the circuit is closed, the device is alwaysin the position shown in Fig. 5, with the line 50 opposite thenormalonarrow. However, the device may be in the normal onposition shown inFigs. 5 and 6 and the circuit still be open; and that is the situationthat exists following a blowing of the device,

upon the flow of an excess current. When such blowing occurs, producinga condition such as shown in Fig. '6, it is necessary to move the device(either clockwise or counterclockwise) substantially to the off positionshown in Fig. 3, with the line 50 opposite the off arrow, and then toturn the device clockwise from the 0d position shown in Fig. 3 to thenormal on position shown in Fig. 5, to make the line 50 travel clockwisefrom the 0d arrow to the normal on arrow. The closing of the circuitcannot be efiected following a blowing save by a movement of the devicefrom the off to the normal on position; which necessitates a preliminarymovement to the oif position.

' If upon the closing of the circuit, the conditions which caused theexcess of current still exist, the device will immediately blow again,and thus again break the circuit. Thus a permanent closing of thecircuit cannot be effected so long as overload conditions exist.

However, like a fuse, the device does not operate upon small transientoverloads. The excess current must be sufficiently great to producevaporization of the mercury; so that there is a time lag in the blowingof the device that varies in inverse sense to the amount of theoverload, just as in a fuse.

I have illustrated my invention only in one preferred form. The presentapplication is intended not only to cover that preferred form but alsois intended to cover the invention generically. For instance, onemodified form of the invention, coming within the scope of my genericclaims herein, is shown and claimed in my co-pending application SerialNo. 317,221, filed November 5, 1928.

While in the specific emobdiment which I have illustrated of myinvention the tube 16 and its restricted conduit passage 18 are withinthe space provided by the main container, so that any liquid conductorwithin such tube and its conduit passage are in a broad sense alsowithin the container in which such tube is positioned, yet in theappended claims when a relation is expressed between liquid conductor inthe conduit passage and liquid conductor in the container the latterliquid conductor refers to that which is in the container but not in theconduit passage.

I claim as my invention 1. An electric circuit controller, comprismg acontainer movable to 0d and normal on positions, a conduit having atubular passage communicating with said container, liquid conductorwithin the space provided by said container and conduit, and twoelectrodes exposed within said space and separated from each otherlengthwise of said passage and positioned to be interconnectible withinsaid space only by liquid conductor contained within and filling a:predetermined length of said tubular passage between said electrodes toallow current flow for a substantial distance in a direction along saidpassage, said electrodes being located with relation to said containerand conduit so that they are interconnected only when the container issubstantially in the normal on position, and said conduit being soshaped and positioned with respect to the container that when thecontainer is in normal on position and said predetermined length of saidtubular passage is not filled with liquid conductor a flow of the liquidconductor from said container into said passage can be obtained only byfirst moving said container, to the off position.

2. An electric circuit controller, comprising a container movable to ofiand normal on positions, a conduit having a tubular passagecommunicating with said container, liquid conductor within the spaceprovided by said container and conduit, and two electrodes exposedwithin said space and separated from each other lengthwise of saidpassage and positioned to be interconnectible within said space only byliquid conductor contained within and filling a predetermined length ofsaid tubular passage between said electrodes to allow current flow for asubstantial distance in a direction along said passage, said electrodesbeing located with relation to said container and conduit so that theyare interconnected only when the container is substantially in thenormal on position, and said conduit being so shaped and positioned withrespect to the container that when the container is in normal onposition and said predetermined length of said tubular passage is notfilled with liquid conductor a flow of the liquid conductor from saidcontainer into said passage can be obtained only by first moving saidcontainer to the ofi position, the tubular passage of said conduitopening into said container at a level sufliciently above the low pointof the container when the latter is in the normal on position that anyliquid conductor discharged from said tubular passage into saidcontainer cannot re-enter the tubular passage while the containerremains in that position.

3. An electric circuit controller, comprising a container movable to offandnormal on positions, a conduit having a tubular passage communicatingat two separate places with said container. liquid conductor within thespace provided by said container and conduit, and two electrodes exposedwithin said space and connectible externally to the circuit to becontrolled and separated from each other lengthwise of said passage andpositioned to be interconnectible within said space by liquid conductorcontained within a predetermined lengthof said tubular passage betweensaid electrodes to allow current flow for a substantial distance in adirection --along said passage, said electrodes being arranged withrelation to said container and conduit and to the circuit to becontrolled so. that the circuit is closed only when thecontainer issubstantially in the normal on position, and said conduit being soshaped and positioned with respect to the container that when thecontainer is in normal on position and liquid conductor in saidpredetermined length of said tubular passage fails to interconnectsaidelectrodes a flow of the liquid conductor from said container into saidpassage can be obtained only by first moving said container to the offposition.

4. An electric circuit controller, comprising a movable container, aconduit having a tubular passage communicating with said container,liquid conductor within the space formed by said container and conduit,two electrodes exposed within said space and connectible to the circuitto be controlled and connectible together within said space by liquidconductor extending through a prede-- termined part of the passage ofsaid conduit, said conduit being so arranged with respect to saidcontainer that the liquid conductor will flow into it from the containeronly when the container is in a definite range of positions and thecircuit between "the electrodes will be closed only when the containeris in a diiierent definite range of positions.

5. An electric circuit controller, comprising a movable container, aconduit having a tubular passage communicating with said container,liquid conductor within the space formed by said container and conduit,two electrodes exposed within said space and connectible to the circuitto be controlled and connectible together within said space only byliquid conductor extending through a predetermined part of the passageof said conduit, said conduit being so arranged that it has one openingwhich is always above the level of the liquid conductor in the containerand another opening into which liquid conductor may flow from thecontainer only when the container is in a definite range of positions.

6. An electric circuit controller, comprising a movable container, aconduit having a tubular passage communicating with said container,liquid conductor within the space formed by said container and conduit,two electrodes exposed within said space and connectible to the circuitto be controlled and connectible together within said space by liquidconductor extending through a predetermined part of the passage of saidconduit,

said conduit being so arranged that it has one opening which is alwaysabove the level of the liquid conductor in the container and anotheropening into which liquid conductor may flow from the container onlywhen the container is in a definite range of positions and so that theliquid conductor can occupy the predetermined part of said passage onlywhen the container is in a difierent definite range of positions.

7. An electric circuit controller, comprising a movable container, aconduit having a tubular passage communicating with said container, aliquid conductor located within the space formed by said container andpassage, two electrodes which may be connected to the circuit to becontrolled and may be connected together within said space by saidliquid conductor, said electrodes being so arranged that they areconnectible together by said liquid conductor only when at the same timethe container is in a given range of positions and liquid conductor isin said conduit, and said conduit being such that when the container isin that given range of positions the liquid conductor remains in theconduitto connect the electrodes so long as it remains liquid but noliquid conductor can flow into the conduit from the container.

8. An electric circuit controller, comprising a movable container, aconduit having a tubular passage communicating with said container,liquid conductor located within the space formed by said container andpassage, two electrodes which may be connected to the circuit to becontrolled and may be connected together within said space by saidliquid conductor, said electrodes being so arranged that they areconnectible together by said liquid conductor only when at the same timethe container is in a given range of positions and liquid conductor isin said conduit, said conduit being such that when the container is inthat given range of positions the liquid conductor remains in theconduit to connect the electrodes solong as it remains liquid, and saidcontainer and conduit being so arranged that liquid conductor can flowfrom said container into said conduit only when the container is movedto a difi'erent range of positions.

-9. An electric circuit controller, comprising a quantity of liquidconductor, movable means for holding said liquid conductor so that theliquid conductor takes different positions according to the position ofsaid holding means, two electrodes which may be connected to the circuitto be controlled and may be connected together by said liquid conductor,said electrodes being so arranged with respect to each other and to saidholding means that they are connectible together by said liquidconductor only when at the same time the holding means is in a givenrange of positions and liquid conductor occupies a definite part of saidholding means which it is impossible to fill or empty bygravity flowfrom or to the rest of said holding means while the holding means is inthat range of positions, said definite part being of tubular form.

10. An electric circuit controller comprising a liquid container havinga passage being movable; a quantity of liquid con-.

ductor in said container; and two circuit electrodes at said passage andsimultaneously engageable by liquid conductor contained in said passage,said liquid conductor being receivable into said passage from thecontainer and being also dischargeable from the passage upon the flow ofabnormal current through said electrodes and the liquid conductorbetween them, said container being shaped to hold the liquid conductorthus discharged and prevent its return to the passage when the containeris in circuit-closing position, and also being shaped to direct returnflow of such discharged liquid toward the passage when the container ismoved from and subsequently returned to said circuitclosing position.

11. An electric circuit controller comprising a movable container havinga normal circuit-closing position, a quantity of liquid conductor withinthe container, a tube of heatresisting insulation having its passagecomarranged for connection to a circuit and connectible together byliquid conductor in and extending along a substantial portion of thelength of said tube and so spaced apart that said liquid conductor formsbetween them a current-path carrying current lengthwise of said tube;said container, tube, and electrodes having a shape and relation (as)which limit the interconnection of said electrodes by liquid conductorto substantially the normal circuit-closing position of the containerand to a current-path completable only through the aforesaid substantialportion of the length of the tube, and (b) which, upon the expulsion ofthe liquid conductor from the tube, prevent its return while thecontainer is in normal circuit-closing position.

12.. An electric circuit controller as set forth in claim 11, with theaddition that said tube is positioned to have a cross-sectional portionof its passage between the electrodes a sufficient distance above thebottom in the container for all circuit-controlling positions of thecontainer that if the tube breaks the entire body of liquid conductormay be held in the container Without interconnecting said electrodes.

13. An electric circuit controller as set forth in claim 11, with theaddition that said container, tube, and electrodes have a shape andrelation which feed the liquid conductor from the container into thetube upon movement of the container from and its subsemunicating withthe container, two electrodes quent return to said normalcircuit-closing above the bottom in the container for allcircuit-controlling positions of the container that if the tube breaksthe entire body of liquid conductor may be held in the container withoutinterconnecting said electrodes.

. 14. An electric circuit controller compris mg a movable containerhaving a normal circuit-closing position, a quantity of liquid conductorwithin the container, a tube of heatresisting insulation having itspassage communicating with the container, two electrodes arranged forconnection to a circuit and connectible together by liquid conductor inand extending along a substantial portion of the length of said tube andso spaced apart that said liquid conductor forms between them acurrent-path carrying current lengthwise of said tube; said container,tube, and electrodes having a shape and relation (a) which, upon theexpulsion of the liquid conductor from the tube, prevent its returnwhile the container is in normal circuit-closing position, and (b) whichconstrain passage of the liquid conductor from the container into thetube only upon movement of the container from and its subsequent returnto said normal circuit-closing position.

15. An electric circuit controller comprising a movable container havinga normal circuit-closing position, a quantity of liquid conductor withinthe container, a tube of heatresisting insulation having one endcommunicating with the container, a conduit which interconnects theother end of said tube with the container, and two electrodes arrangedfor connection to a circuit and connectible together by liquid conductorin and extending along a substantial portion of the length of said tubeand s0 spaced apart that said liquid conductor forms between them acurrent-path carrying current lengthwise of said tube; said container,conduit, tube, and electrodes having a shape and relative positioningwhich, upon the expulsion of the liquid conductor from the tube, preventits return while the container is in normal circuit-closing position.

16. An electric circuit controller as set forth in claim 15, with theaddition that said container, conduit, tube, and electrodes have a shapeand relation which feed the liquid conductor from the container throughthe conduit and into the tube upon movement of the container from andits subsequent return to said normal circuit-closing position.

17. An electric circuit controller as set forth in claim 15. with theaddition that said tube is positioned to have a cross-sectional portionof its passage between the electrodes a suflicient distance above thebottom in the container for all circuit-controlling positions of thecontainer that if the tube breaks the entire body of liquid conductormay be held in the container without interconnecting said electrodes.

19. An electric circuit controller as setv forth in claim 15, with theaddition that said container, conduit, tube, and electrodes have a shapeand relation which limit the interconnection of said electrodes byliquid conductor to substantially the normal circuit-closing position ofthe container and to the liquid conductor within the tube, and that saidtube is positioned to have a cross-sectional portion of-its passagebetween the electrodes a suiticient distance above the bottom in thecontainer for all circuit-controlling positions of the container that ifthe tube breaks the entire body of liquid conductor may be held in thecontainer without interconnecting said electrodes.

20. An electric circuit controller as set forth in claim 15, with theaddition that said container, conduit, tube, and electrodes have a shapeand relation which feed the liquid conductor from the container throughthe conduit and into the tube upon movement of the container from andits subsequent return to said normal circuit-closing position, and thatsaid tube positioned to have a cross-sectional portion of its passagebetween the electrodes a suificient distance above the bottom in thecontainer for all circuit-controlling positions of the container that ifthe tube breaks the entire body of liquid conductor may be held in thecontainer without interconnecting said electrodes.

21. An electric circuit controller as set forth in claim 15, with theaddition that said container, conduit, tube, and electrodes have a shapeand relation which both limit the interconnection of said electrodes byliquid conductor to substantially the normal circuitclosing position ofthe container and to the liquid conductor within the tube, and feed theliquid conductor from the container through the conduit and into thetube upon movement of the container from and its subsequent return tosaid normal circuit-closing position, and that said tube is positionedto have a crosssectional portion of its passage between the electrodes asufficient distance above the bottom in the. container for allcircuit-controlling positions of the container that if the tube breaksthe entire body of liquid con-ductor may be held in the containerwithout interconnecting said electrodes.

22. An electric circuit controller, comprising a container movable toofi and normal on positions, a conduit having a tubular passagecommunicating with the container, liquid conductor within the spaceprovided by the container and conduit, two electrodes exposed withinsaid space and positioned to be interconnectible along a path extendinglengthwise through a current-limiting portion-of said tubular passage bysaid liquid conductor when it is contained within said tubular passage,said container and conduit being provided with means to cause saidliquid conductor to close the circuit to be controlled operable bymoving the container from off to normal onposition, and saidconduit-passage opening into the container at two separate places, aportion of the conduit-passage near each of said places being above theliquid conductor level in the container when the container is in normalon position in a manner to prevent flow of the liquid conductor from thecontainer into said passage when the container is in such normal onposition.

23. An electric circuit controller, comprising a container, liquidconductor in the con tainer, a conduit communicating with the container,and two electrodes exposed and spaced to be interconnectible along apath extending lengthwise of the passage of said conduit by liquidconductor within a predetermined current-limiting portion of saidpassage, said conduit having one end of its passage opening into thecontainer above the liquid level in the container in a definite firstposition of the conduit and having the mouth of the other end of itspassage opening into the container below the liquid level in thecontainer in said definite first position, said conduit having mountingmeans and being movable on such mounting means to a definite secondposition in which said last-mentioned passage mouth is above the liquidlevel in the container, and said conduit being lower at an intermediatepoint than at pointson either side of that point whenit is in the secondposition so that it will retain liquid conductor by gravity in thepredetermined passage-portion between electrodes when it is in thesecond position to interconnect the electrodes.

24. An electric circuit controller as set forth in claim 23, with theaddition that the conduit and container are angularly together movableon the mounting means, and that the predetermined portion of the conduitpassage. between electrodes is higher than the liquid level in thecontainer in all operating positions of the conduit and container.

25. An electric circuit controller, comprisinga container, liquidconductor in the conanemia tainer, a conduit communicating with thecontainer at each end of its passage, and two electrodes exposed andspaced to be interconnectible by liquid conductor along a path extendinglen thwise through a predetermined portion oi the passage of saidconduit, said conduit having a liquid-receiving mouth at one end of itspassage opening into the container below the liquid level in thecontainer in a definite first position ofthe conduit, in which firstposition the predetermined passage portion between electrodes is abovethe liquid level in the container, said conduit being movable to adefinite second position in which the liquid-receiving passage mouth isabove the passage-portion between electrodes, and said liquid-receivingmouth being shaped to dip up liquid conductor and feed it through saidconduit into said passage-portion between electrodes as the conduit ismoved from the first position to the second.

26. An electric circuit controller as set forth in claim 25, with theaddition that the conduit and container are together movable to saidfirst andv second definite operating positions, and that a part of saidpredeter- I to two definite positions in both of which one end of theconduit passage opens into the container above the liquid level in thelatter, the other end of said conduit passage opening into the containerabove and below the liquid level in the latter when the conduit is insaid two positions respectively, said conduit being shaped to containliquid conductor by gravity in the predetermined passageportion betweenelectrodes when it is in the position where both its ends are above theliquid level in the container and being positioned to drain liquidconductor contained therein into the container in the other of said twopositions.

28. An electric circuit controller, comprising a container, a tubularconduit opening at both ends into a common space in said container, saidconduit having a passage-portion which is higher at one end than at theother when the circuit through the circuitcontroller is closed and whichincludes a current-limiting portion of predetermined dimensions, liquidconductor within the 7 space provided by said container and conduit, andtwo electrodes associated with said conduit to be interconnectible bysaid liquid conductor extending through said currentlimitingconduit-portion to provide a current path lengthwise thereof; saidcircuit controller being provided with means for feeding said liquidconductor at will into the aforesaid passage-portion at the lower endthereof.

29.- An electric circuit controller having a movable member, andcomprising a container, a tubular conduit opening at both ends into acommon space in said container, said conduit having a passage-portionwhich is higher at one end than at the other when the circuit throughthe circuit controller is closed and which includes a current-limitingportion of predetermined dimensions, liquid conductor within the spaceprovided by said container and conduit, and two electrodes associatedwith said conduit to be interconnectible by said liquid conductorextending through said current-limiting conduit-portion to provide acurrent path lengthwise thereof; the aforesaid passage-portion be1ngassociated with said movable member to have said liquid conductor fedinto it at the lower end thereof and discharged from it respectively bydifferent movements of said movable member.

30. An electric circuit controller having a movable member, andcomprising a contamer, a tubular conduit opening at both ends into acommon space in said container, sa d conduit having a passage-portionwhich is higher at one end than at the other when the circuit throughthe circuit controller is closed and which includes a current-limitingportion of predetermined dimensions, liquid conductor within the spaceprovided by said container and conduit, and two electrodes associatedwith said conduit to be interconnectible by said liquid conductorextending through said current-limiting conduit-portion to provide acurrent path lengthwise thereof; the aforesaid passage-portion beingassociated with said movable member to have said liquid conductor fedinto it at the lower end thereof by movement of said movable member.

31. An electric circuit controller having a movable member movable tooff and normal on positions,'and comprising a container, a tubularconduit opening at both ends" within said container, said conduit havinga current-limiting portion which is of predetermined dimensions and ishigher at one end than at the other when said movable member is innormal on position, liquid conductor within said container and conduit,and two electrodes associated with said conduit to be interconnected bysaid liquid conductor extending through said current-limitingconduit-portion but otherwise insulated from each other; saidcurrent-limiting conduit-portion being associated with said movablemember to have liquid conductor fed to it at its lower end when themovable member is moved from off to normal on position and to haveliquid conductor discharged from it when the movable member is movedfrom normal on to 01f position.

32. An electric circuit controller having a movable member movable tooff and normal on positions, and comprising a container, a tubularconduit opening at both ends within said container, said conduit havinga current-limiting portion which is of predetermined dimensions and ishigher at one end than at the other when said movable member is innormal on position, li uid conductor within said container and con uit,and two electrodes associated with said conduit to be interconnected bysaid liquid conductor extending through said current-limitingconduit-portion but otherwise insulated from each other; saidcurrent-limiting conduit-portion being associated with said movablemember to have liquid conductor fed to it at its lower end when themovable memher is moved from off to normal on position. i

33. A liquid conductor current-limiting circuit controller, comprisingapair of electrodes, a conduit forming a passage open at both ends, partof said conduit comprising a body of heat-resisting insulating materialhaving a current-limiting tubular bore therethrough forming a part ofsaid passage, said passage being shaped to retain a liquid conductortherein and in contact with said electrodes by gravity when in a normalon? position only, a casing completely enclosing said passage and saidelectrodes, and a body of liquid conductor within said casing; saidcasing forming an expansion chamber communicating with the open ends ofsaid passage and extending sufliciently below portions of said passagewhen in its on position so that liquid conductor expelled from saidpassage will fall to a lower level in the chamber, and in all operatingpositions extending suiiiciently below at least one electrode so thatthe electrodes can not be connected by said liquid conductor exceptlongitudinally through said bore; said casing and included parts beingrotatable to an off position in which the liquid conductor will flowfrom at least a portion of said bore and disconnect said electrodes, andbeing so constructed that liquid conductor can be fed into said bore toconnect said electrodes only as said passage is rotated to said onposition.

84. An electric circuit controller, comprising a container, liquidconductor within the container, two electrodes, and a conduit shaped sothat it can hold liquid conductor within it, said conduit including as aporthrough the control tube, said container being adapted to act as adischarge chamber for liquid conductor ejected from the control tube.

35. An electric circuit controller, comprising a container, twoelectrodes, a quantity of liquid conductor, a refractory control tubehaving a current-limiting bore small enough to require an appreciablepressure to force liquid conductor through it, and a feed conduitcommunicating with one end of said bore and through which liquidconductor may be fed by hydrostatic pressure exerted by the weight of along and relatively narrow column of liquid conductor as it is fedthrough the conduit, said control tube and feed conduit together forminga receptacle capable of holding liquid conductor and opening into thecontainer at both ends, and said circuit controller including means tocollect liquid conductor discharged from the control-tube bore andreturn it at will to saidhere through the feed conduit.

36. An electric circuit controller, comprising a container, twoelectrodes, a quantity of liquid conductor, a refractory control tubehaving a current-limiting bore, and a feed conduit communicating withone end of said bore, said control tube and feed conduit togetherforming a receptacle capable of holding liquid conductor and openinginto'the container at both ends, and said circuit controller includingmeans to collect liquid conductor discharged from the control-tube boreand operable at will to return it to said bore through the feed conduitin order to connect the electrodes by liquid conductor and to withdrawliquid conductor from the control-tube bore in order to disconnect theelectrodes.

37. An electric circuit controller, comprismeans In witness whereof, Ihave hereunto set my hand at Indianapolis, Indiana, this 12th day ofJune, A. D. one thousand nine hundred and twenty eight.

STANLEY S. GREEN.

ing a container, two electrodes, a quantity of liquid conductor, arefractory control tube having a current-limiting bore, and a feedconduit communicating with one end of said bore, said control tube andfeed conduit together forming a receptacle capable of holding liquidconductor and opening into the container at both ends, and said circuitcontroller including means to collect liquid conductor discharged fromthe control-tube bore and operable at will to returnit to said borethrough the feed conduit in order to connect the electrodes by liquidconductor and also operable at will to break the circuit to becontrolled.

